Electric appliance having pin contacts and method of manufacturing the same



Jan. 17, 1928. 1,656,856

W. J. GAGNON ELECTRIC APPLIANCE HAVING PIN CONTACTS AND METHOD OFMANUFACTURING THE SAME Filed'Dec 20 1926 IIVVEIVTOR MTG/van N i m AATTORNEYS Y 45 by the invention disclosed in m Patented Jan. 17, 1928.

UNITED, STATES g 1,656,856 PATENT OFFICE.

WILLIAM J. GAGNON, OF BRIDGEPORT, CONNECTICO'T, ASSIGNOR TO THE CHAINMANUFACTURING COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OFCONNECTICUT. I

ELECTRIC APPLIANCE HAVING PIN CONTACTS AND METHOD OF MANITFACTUBINGTIEIES A]IIE. p

' Applicatlonflled December 20, 1926. Serial No. 155,959.

My invention relates to electric appliances having pin contacts, andmethod of manufacturing the same, and particularly to appliances havingfrangible bases to which 6 said pins are riveted. The object of .minvention is to so form the frangible bo y at the point at which the inis attached, and to so shape and attach t e pin thereto, that danger ofbreakage of the frangible body in- 1 cident to the riveting operatlon isminimized.

In theaccompanying drawings- Fig. 1 is a vertical section through theinsulating base of an audion tube showing two pins attached thereto, anda third pin in position for attachment;

Fig. 2 is a top plan view of an audion base showing four pins securedthereto in accordancewith my invention;

Figs. 3', 4 and 5 are enlarged sectiona views illustrating successiveoperations-upon a pin during the attaching operation;

' Fig. 6 is a view similar to Fig. 5, but illustrating the position ofthe attached pin to a base of different thickness;

1 Fig. 7 is a'section drawn to enlar ed scale and illustrating aslightly modi ed construction; and

Fig. 8 is a similar view illustrating a further modification.

A heavy percentage of breakage is experienced in the attachment ofcontact pins to the insulating bases of audion bulbs. These bases arecommonly made of porcelain,

or glass, or bakelite, suitably apertured to permit the attaching end ofthe pin to be passed therethrough. To secure this end in position it iscommon to resort to a spreading or riveting operation, which results inpressure upon the relatively thin diaphragm of the frangible basematerial. This breakage percentage is rticularly high when the pins usedare 0 the solid type. I have succeeded in reducing this loss materiallycopending application Ser. No. 56,291, file September 14, 1925, in whichI have disclosed a tubular sheet metal pin provided intermediate itsends with an open shoulder enlargement, which during the offset orrivetin operation forms a cushion which material y lessens the strainupon the frangible material of the base. A p

However, even with this cushioning collapsible abutment shoulder on thepin, all losses are not avoided. This is, in large part due to thefactthat there-is an unavoidable variation in the thickness of the diaphragmof the base incident to its manufacture. Consequently, the upsettingtools which are ad- ]usted to approach each other a uniform distance,bear heavily upon the basematerial and rupture.

Where the thickness of the dia hragm is below normal the upsetting tools0 not approach each other sufficiently closely to ef-' If)ect the firmattachment of the pin to the ase.

These difliculties have beensolved, according to the present invention,by so' forming the base at the point of engagement with the pin end thata relatively'great tolerance mechanical connection between the pin andthe base,'and also relievin rupture strains incident to t e upsettingoperation. j

Referring to the drawings, an audion base 15 of conventional type hasbeen illustrated in Figs. 1 and 2, the diaphragm 16 of the base beingpierced in usual fashion to er mit the passage of the attachin ends 0the pins therethrough. I have s own longitudinally split rigid tubularsheet metal pins of the type described in my copending applicationmentioned, since I regard these pins as the best and most economicalforv use. Pins of this ty e are preferably provided intermediate theirends with a collapsible cushioning abutment shoulder 18, although I havefound that with the features hereinafter described a cushioning shoulderof this type is not necessary. In

{is afforded with respect to the. thickness of I "the base, while.nevertheless insuring a good the base from 6 -After a pin has beeninserted preparatory to upsetting, it is held in position by a suitablesupport engaged with the lower face of the shoulder 18. The upsettingoperation preferably comprises two steps, first, a

. 'tact with t and spreads the split tongues 24 radially.

The spreader is outward in all directions. so shaped that it does notbearagainst the diaphragm 16 of the base, and consequently little or norupturing stress is exerted. The tongues 24 are, however, pressedoutward over the relatively sharp lip 20, forming the upper margin ofthe aperture, but a firm engagement therewith is not established by Ithe spreader.

The action of the spreader is followed by the action of the tubularupsetter tool 22. The working end of the latter is inwardly bevelled at25, as indicated in Figs. and 6, so that onl its 'outer edge 26 comes incon lie tongues 24. The travel of the spreader 22 toward the diaphragm16 of the base is so predeterminedthat the working edge 26 of theupsetter. does not force the tongues 24 down to the bottoms of. the

recesses 19. Consequently, no severe or rupturin pressure is exertedthereby upon the diap ragm 16, while, nevertheless, the

ton ues 14 are bent down into the recesses 19 y su cientl to firmly gripthe lip 20 of the recess an thus securely rivet the pin in position. 1

The fact that the upsetter 22 does not bear against the diaphragm 16when the latter is of normal thickness, insures a generous tolerance forvariation in the diaphragm thickness, without danger of rupturingstresses being exerted by the upsettcr 22 upon the diaphragm.Nevertheless a firm connection is established even when the diaphragm isof sub-thickness, as illustrated in. Fig. 6, since the upsetting of thetongues 24 over thelip 20 is sufficient even under such conditions tofirmly rivet the pin to the base.

In Fig. 7 I have shown a recess 19 of slightly different shape from thatshown in Figs. 3 to 6, the outer margin of the recess beingsubstantially parallel with the pin axis.

In Fig. 8, instead of a recess, I have shown a lip 27 raised above theupper surface of the diaphragm. This necessitates a mouse somewhatlonger pin neck, but strengthens scribed, so long as the upsettingtool22 depresses the tongues 24 only toward, but not to, the surface of thediaphragm 16.

Breakage is practically eliminated by an attachment of this character,and since breakage resultsndt only in the loss of the base 15, but inthe discard of a plurality of pins as well, the saving is very material.

While I prefer to use pins of the character shown, it will be readilyunderstood that the present invention may he applied to the attachmentof pins of various types, particularly to other types of tubular pins.It will be understood, therefore, that the accompanying illustration andthe foregoing de-' scription are merely illustrative of the thoughtswhich underlie my invention, the scope of which is pointed out in thefol* lowing claims.

I claim 1. The method of attaching a contact pin to a frangible bodyhaving a pin holetherethrough, and a lip at the mouth of the hole, saidlip being above the level of the surrounding surface of the body, saidmethod comprising the steps of mushrooming the projecting pin end anddeflecting the marginal portion of the mushroom toward but not againstthe surface by pressure applied to said marginal area of the mushroombeyond thearea of the lip.

'2. The method of attaching a contact pin to a frangible body having apin hole theret-hrough, and a lip atthe mouth of the hole, said lipbeing above the level of the surrounding surface of the body, saidmethod comprising the steps ofmushrooming the projecting pin end andcausing the latter to bind against the lip by deflecting pressureapplied to the mushroom beyond the area of the lip, and causing theportions of the mushroom to which said pressure is applied to approach,but not bear against, the surface of the frangible body.

3. A frangible body perforated to receive a contact pin, and'having onone face and at the mouth of the perforation a marginal lip above thelevel of the surrounding surface, incombination with a contact pinliaving a shoulder bearing against: the opposite face of said body, anda mushroonied end frictionally engaging said lip, the margins of saidmushroom beyond said lip approaching, but out of contact with, thesurface which it overlies.

In testimony whereof I have signed my name to this specification.

WILLIAM J. GAGNON

